module Regexp::Parser

def self.escape(token)
  case token.token
  when :backspace
    @node << EscapeSequence::Backspace.new(token)
  when :escape
    @node << EscapeSequence::AsciiEscape.new(token)
  when :bell
    @node << EscapeSequence::Bell.new(token)
  when :form_feed
    @node << EscapeSequence::FormFeed.new(token)
  when :newline
    @node << EscapeSequence::Newline.new(token)
  when :carriage
    @node << EscapeSequence::Return.new(token)
  when :space
    @node << EscapeSequence::Space.new(token)
  when :tab
    @node << EscapeSequence::Tab.new(token)
  when :vertical_tab
    @node << EscapeSequence::VerticalTab.new(token)
  when :control
    @node << EscapeSequence::Control.new(token)
  else
    # treating everything else as a literal
    @node << EscapeSequence::Literal.new(token)
  end
end